Perturbation of the Relative Contribution of Molecular Chaperones in the Endoplasmic Reticulum

Kiichiro Totani; Kaoru Arima; Taiki Kuribara; Yui Satake; Makoto Hirano

doi:10.1021/acsomega.9b04445

Perturbation of the Relative Contribution of Molecular Chaperones in the Endoplasmic Reticulum

ACS Omega. 2020 Mar 24;5(13):7399-7405. doi: 10.1021/acsomega.9b04445. eCollection 2020 Apr 7.

Authors

Kiichiro Totani¹, Kaoru Arima¹, Taiki Kuribara¹, Yui Satake¹, Makoto Hirano²

Affiliations

¹ Department of Materials and Life Science, Seikei University, 3-3-1 Kichijoji-Kitamachi, Musashino, Tokyo 180-8633, Japan.
² Department of Pharmacy, Yasuda Women's University, 6-13-1 Yasuhigashi, Asaminami-ku, Hiroshima 731-0153, Japan.

Abstract

We demonstrate the preferential orders of molecular chaperones glucose-regulated protein 94 (GRP94), binding immunoglobulin protein (BiP), and calreticulin (CRT) in an endoplasmic reticulum (ER) fraction from rat liver using columns conjugated with denatured myoglobin, RNase A, or β-lactoglobulin as client proteins in the presence or absence of ATP. The results showed that BiP, CRT, and GRP94 preferentially contributed myoglobin, RNase A, and β-lactoglobulin, respectively, in the presence of ATP. In the absence of ATP, GRP94 and CRT preferentially recognized misfolded myoglobin (α-helix-rich protein), whereas BiP preferentially recognized misfolded RNase A (α-helix/β-sheet mixed protein) and β-lactoglobulin (β-sheet-rich protein). The preferential order of ER chaperones may be dynamically regulated by ER conditions and the higher-order structure of client proteins.